package org.bouncycastle.asn1.pkcs;

import java.math.BigInteger;
import java.util.Enumeration;

import org.bouncycastle.asn1.ASN1Encodable;
import org.bouncycastle.asn1.ASN1EncodableVector;
import org.bouncycastle.asn1.ASN1Sequence;
import org.bouncycastle.asn1.DERInteger;
import org.bouncycastle.asn1.DERObject;
import org.bouncycastle.asn1.DERSequence;

public class DHParameter extends ASN1Encodable {
    DERInteger p, g, l;

    public DHParameter(BigInteger p, BigInteger g, int l) {
        this.p = new DERInteger(p);
        this.g = new DERInteger(g);

        if (l != 0) {
            this.l = new DERInteger(l);
        } else {
            this.l = null;
        }
    }

    @SuppressWarnings("rawtypes")
    public DHParameter(ASN1Sequence seq) {
        Enumeration e = seq.getObjects();

        p = (DERInteger) e.nextElement();
        g = (DERInteger) e.nextElement();

        if (e.hasMoreElements()) {
            l = (DERInteger) e.nextElement();
        } else {
            l = null;
        }
    }

    public BigInteger getP() {
        return p.getPositiveValue();
    }

    public BigInteger getG() {
        return g.getPositiveValue();
    }

    public BigInteger getL() {
        if (l == null) {
            return null;
        }

        return l.getPositiveValue();
    }

    public DERObject toASN1Object() {
        ASN1EncodableVector v = new ASN1EncodableVector();

        v.add(p);
        v.add(g);

        if (this.getL() != null) {
            v.add(l);
        }

        return new DERSequence(v);
    }
}
